<html>
<head>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
var treeTraversal = $("div").children().map(function(){
return this.tagName;}).get().join(", ");
$("div").after("<h2>" + treeTraversal + "<h2>");
});
</script>
</head>
<body>
<div> This is a div element. My child is:
<p>
<span></span>
</p>
</div>
</body><p>
In this example, $("div").children will only return P, and not P + SPAN, because children() only traverse a single level down the DOM tree.
</p></html>